I have installed Jenkins by deploying its WAR file to Tomcat. On typing

http://localhost:8080/jenkins

In browser, jenkins home page is opening which means jenkins is successfully installed. I configured system settings, gave jdk and maven path and save them. Then to install plugins, I clicked on Jenkins->Manage plugins and clicked on Available tab but could not find any plugins. I tried three solutions:

Configured proxy for Jenkins by going to Jenkins->Manage Plugins->Advanced(did not find plugins)

Restarted server, refreshed browser and went to Jenkins->Manage plugins->Available (still did not find any plugins). So, I read somewhere that we have update plugins forcefully if they are not updated automatically. So, went to Jenkins->Manage Plugins->Advanced and clicked the tab 'Check now' (Still did not find any plugins on clicking on Available tab).

Finally I read somewhere that if we add the pluginGroup 'org.jvnet.hudson.tools' to settings.xml file of maven, problem may be resolved. So, added the corresponding code to settings.xml:

Then I tried again but still could not find any plugins in

Jenkins->Manage plugins->Available

If any other solution is there which can resolve this problem please let me know.

25 Answers
25

The problem may be that your browser proxy settings are not configured properly.

Jenkins doesn't retrieve the plugin list directly from the update center, it tells your browser to retrieve it and post it back to Jenkins. So the HTTP proxy settings within Jenkins are ignored for this step.

So if you are using a browser that is configured to only work within your network, to connect to local servers such as a Jenkins instance, then you won't be able to update the plugin list.

Well something changes in our corp infra over the weekend - so while Jenkins gives 503 for URL: http://updates.jenkins-ci.org/update-center.json in "Manage Plugins", I can see the JSON at that URL in the same browser...
– simon.wattsJul 23 '18 at 12:05

This was so frustrating... Not because of difficulty but lack of clarity and good documentation, at least for the issues I encountered. I ended up having to set up the Manage Plugins -> Advanced -> HTTP Proxy Configuration in a very specific, picky way. If I didn't do exactly this, minus the last noted thing on the bottom, I could not get this working. Maybe it's my work's firewall, maybe it's jenkins, either way give this a shot if you haven't been able to successfully update your proxy settings. I used the Validate Proxy tool in the menu. I'll very briefly describe the infographic basics below

Don't add http:// or https:// to your Server field

Use your jenkins credentials for Username and Password, not your proxy credentials (if that's even applicable)

I had this issue when using nginx as a secure reverse proxy. I needed to update the url from which to download the updates list, as suggested above, only with https to prevent mixed content errors in chrome.

I came across this SO answer while I was experiencing the same issue. When I would click "Check Now" to force Jenkins to download the latest list, my browser would just hang. It wasn't until I tailed the Jenkins log that I found this here:

Looks like the issue has to do with how I've put Jenkins behind a reverse proxy and enabled the option to prevent Cross Site Request Forgery. Once I disabled that, the "Check Now" completed within 30 seconds.

If you're using Chrome
Go to: Manage Jenkins → Manage Plugins → Advanced, then click Check now in the bottom right-hand corner. Then click a shield icon in the address bar, click Load anyway and Jenkins will start to update plugins. In Firefox this icon is situated on the left side of address bar, near back button.

This answer is specific to Windows 10. If you use the installer that Jenkins now comes bundled as, Jenkins will get installed as a service. By default, the service runs under the Local System account. You have to change it to run under the Network Service account in order for Jenkins to be able to connect with the plugin update service. If you have Administrator privileges on the system then these steps should help:

Open Command Prompt.

Type in Services.msc and hit enter.

The Services window should be open now.

Locate the Jenkins instance in the list.

Right click on it and click Properties.

Go to the Log On tab (should be the second one).

There should be 2 radio buttons.

Local System Account (selected)

This Account (unselected)

Select This Account.

Type in Network Service in the text box.

Provide your windows password.

Hit Apply and OK.

Restart the Jenkins service.

Reload Jenkins in browser.

For added measures, you could also add a rule in Windows Firewall (or any other Firewall that you may be using) to allow outbound requests from Jenkins. Point to the jenkins.exe application that should be located in the installation directory of Jenkins for this rule.

I hate to admit this but it might save someone else some time...I could not find a particular plugin when searching the available list. I learned the hard way that plugins which are already installed to Jenkins don't show in the "available" list...there it was on the "installed" list, already installed, I just didn't realize it. Now I'll check "installed" before searching "available".

not sure why/how it worked, but after doing below steps, i was able to see the 'available' plugins :
1. Go to Manage Jenkins
2. Click 'Reload Configuration from Disk'. It takes a minute or two to reload jenkins
3. Manage Plugins -> Available.